Soft X-ray beamline BL1N2 at Aichi Synchrotron Radiation Center and its industrial use.

BL1N2 is a soft X-ray XAFS (X-ray absorption fine structure) beamline that is well suited for industrial use. User service started in 2015. The beamline is a grazing optical system with a pre-mirror, an inlet slit, two mirrors for three gratings, an outlet slit and a post-mirror. Light of 150 eV to 2000 eV is available, and K-edge measurements of elements from B to Si are covered. The O K-edge is most often measured; transition metals such as Ni and Cu at their L-edges and lanthanoids at their M-edges are also often measured. Here, basic information about BL1N2, the effect of ageing by synchrotron radiation to remove mirror contamination, and a compatible sample handling system and transfer vessels to allow a one-stop service at three soft X-ray beamlines at AichiSR are described.

A new EXAFS method for the local structure analysis of low-Z elements.

A unique analytical method is proposed for local structure analysis via extended X-ray absorption fine structure (EXAFS) spectroscopy. The measurement of electron energy distribution curves at various excitation photon energies using an electron energy analyzer is applied to determine a specific elemental Auger spectrum. To demonstrate the method, the N K-edge EXAFS spectra for a silicon nitride film were obtained via simultaneous measurement of the N KLL Auger and background spectra using dual-energy windows. The background spectrum was then used to remove the photoelectrons and secondary electron mixing in the energy distribution curves. The spectrum obtained following this subtraction procedure represents the `true' N K-edge EXAFS spectrum without the other absorptions that are observed in total electron yield N K-edge EXAFS spectra. The first nearest-neighbor distance (N-Si) derived from the extracted N K-edge EXAFS oscillation was in good agreement with the value derived from Si K-edge analysis. This result confirmed that the present method, referred to as differential electron yield (DEY)-EXAFS, is valid for deriving local surface structure information for low-Z elements.

Photoemission study on the valence band of a ß-FeSi2 thin film using synchrotron radiation.

Resonant and constant-initial state photoemission spectroscopies using synchrotron radiation were applied to investigate the valence-band electronic structure of a semi-conducting ß-type iron-disilicide (ß-FeSi(2)) thin film. The results clearly indicated that the component elements, iron (Fe) and silicon (Si), contribute differently to the valence band features; the Fe 3d orbitals mainly concentrate in the top region of the valence band while the Si 3s and 3p orbitals spread over the wide region of the valence band. The ß-FeSi(2) thin film showed a typical p-type semi-conducting nature with a work function of 4.78 eV. The ß-FeSi(2) film showed the Fe M(1)VV Auger lines around the kinetic energy of 88 eV. It would be expected from these observations that there exist strong interactions between iron and silicon atoms in the ß-FeSi(2) film resulting in orbital mixing and band formation.